A switching contact arrangement has been disclosed as a component of a low-voltage circuit breaker in U.S. Pat. No. 5,517,164.
The contact force which acts on the switching contacts of circuit breakers is applied by stressing the contact force springs which have been mentioned, during the connection process. This is done by way of a drive apparatus which is part of the circuit breaker and whose switching movement is essentially constant throughout the intended life of the circuit breaker. In contrast, erosion of the switching contacts increases the travel of the contact lever, so that the contact force decreases in a corresponding manner to the erosion. If the aim is to ensure that an adequate contact force is achieved even toward the end of the life of a switching contact arrangement, appropriate design of the contact force springs can lead to an undesirably high contact force when their switching contact arrangement is new. This results in a correspondingly large amount of energy being required for the drive apparatus.